Three-wire meter.



No. 796,070.' I PATENTEE AUG.I1,1905. y if T. DUNCAN. f

, THREE WIRE METER.

APPLICATION FILED ooT.1o,19o4. l l zsHEETs-SHEET 1. ,2

f @9' X/WMMM T. DUNCAN. J

THREE WIRBMETBR APPLICATION FILED ooT.1o.1so4. l l v 2sII`EBTs-sHB1JT2,'

'zr-4 I' i f8 me' :l GRAHAM "mu mlmuwm lumai'. I

[PATENTED AUG.1,.1905. y

NITED STATES/j.

PATENT` oFFoE.

THOMAsDUNoAN, -or LAFAYETTE, INDIANA.

THREE- WIRE METER.

Specification of Letters Patent.

'Patented Allg- A1, 190 5.

muy Il@ Application filed october 1o', 1904.. seriaiNo. 227,857.

, To all whom t may concern.-

Beit known that I, THOMAS DUNCAN, a citivzen of the United States,residing at Lafayette, in the county of Tippecanoe and State of Indiana,have invented a certain new and useful Improvement in Three-Wire Meters,of which the followingis a full, clear, concise, and eX-f actdescription, reference being had -to the accompanying drawings, forminga part of vthis specification.

My invention relates to wa-ttmeters of the .portion of the source ofcurrent-supply.

When either main conductor is thus open, the meter is obviously thrownout of service; but this may be immaterial to the consumer, who securesthe service of the side of theV system remaining intact free.

It is the object of my invention to provide an improved arrangement forthe meter whereby it can operate when either or both sides of athree-wire system are in service, so that the consumer may not defraudthe company by an intentional interruption of a main conductor.

. In accordance with my invention the pressure-winding of the meter isconnected with the neutral conductor in such a manner that a portion ofeach pressure-winding is included in each side ofthe system, so thateach side ofthe system will have a current-coil and a pressure-coil ofthe meter in circuit therewith to produce turning effort as a result ofthe current flowing in the corresponding side of the system.

The invention inds a very useful yembodiment in commutated meters, andin adapting the invention to this class of meters the pressure orarmature winding is distributed-in two sets of armature-coils, each setpreferably having a set Yof commutator-segments, therev being also twopairs or sets of brushes, one for one set of armature-coils and theother for the other set of armature-coils. VThe commutator-segments arepreferably aggregated cure the results desired.

,to constitute two distinctcommutators, each having a pair of thebrushes.

One brush of each pair is connected with an outside main conductor,while the other brush of each pair is connected with the neutralconductor to se- I will explain my invention more fully by reference tothe accompanying drawings, in wliichj Figure 1 is a diagrammatic viewshowing the connections of my improved meter in a system of electricaldistribution. Fig. 2is a view somewhat more diagrammatic than Fig. 1,illustrating even more clearly the circuit connections. Fig. 3 is afurther diagrammatic view illustrating in a more simplified form thecircuit connections, both sides of the system being shown intact. Fig. 4is a View similar to Fig. 3, illustrating the upper main open at a fuse,the lower side of the system alone remaining intact, but in operativeconnection with the'meter. Fig. 5 shows, diagrammatically, a connectionof the meter as in the prior art, showing how the purpose of the meteris defeated. Fig. 6' illustrates another connection of the prior art,again illustrating how the purpose of the meter may be defeated. Fig. 7illustrates the connections of the meter of my invention, showing howthe interruption of the neutral conductor will notmodify the function ofthe meter.

Lilie parts are indicated by similar characters of reference throughoutthe different ligures.

The system illustrated being a direct-current system, the meter is acommutated meter, having one field-coil 1 in circuit with an outsidemain 2 and another ield-coil 3 in circuit with an outside main 4, whilethe commutator-brush 5, engaging the upper commutator 6, is connectedwith the main 4, and a companion commutator-brush 7 is connected withthe neutral conductor 8,' the commutator-brush 9 engaging the lowercommutator 10 being also connected Vwith the neutral conductor 8, whilethe companion commutator-brush 11 is connected with the upper main 2.The commutators G Iand lOare conncted with windings 12 and 13 that aresubdivided into armature-coils that are connected with thecommutator-segments in a manner well understood to those skilled in theart. These armature-coils of both windings tors. The armature-windingsare mounted l upon the meter-shaft 14 and are disposed between the coils1 and 3. Each armature- A winding preferably has a starting-coil in cir-Referring more particularly to Figs. 3 toA 7, inclusive, fuses 19, 20,and 21 are included in the two outside main conductors and the neutralconductor, respectively. Hitherto dishonest consumers have opened one orthe other of these fuses, enabling them to secure the services of oneside of this system without compensation, as the meter would fail toregister. By subdividing the pressure-winding of the meter in the mannerthat has been specified, so that one portion of the winding will beconnected in one side of the system and the other portion of the windingin the other side of the system, such an intention is defeated, forthen, practically speaking, the meter is transformed from a three-wiremeter to a double meter. Nor can the object of my inventionA be defeatedby opening the neutral conductor on both sides of its connection withthe pressure-windings, as indicated in Fig. 7, for then the system istransformed into the Brush system of distribution, whereof the .lamps orother consuming means 22 operate between both sides of the system, thecombined pressure-winding of the meter being subject to the pressurebetween the outside mains 2 and 4, causing the said meter proper tooperate, notwithstanding the separation of the neutral conductor. Thus,no matter what may be the manipulation or interruption of l the mainconductors or the neutral conductor one-half of the pressure-winding iseither subject to the pressure between the neutral and anI outside mainconductor or the entire pressure-winding is subject to the pressurebetween the outside mains. Thus, if the sys- Y tem is one wherein apressure of two hundred and twenty volts obtains between two outsidemain conductors, each half of the pressure-winding when properly incircuit will be subject to a pressure of one hundred and ten volts, andthe entire pressure-winding when the neutral conductor is removed fromkcircuit, as indicated in Fig. 7 will be subject t0 a pressure of twohundred and twenty volts. The energy is therefore always-properlyrecorded when current is being supplied, whether fuses are intentionallyor unintentionally excluded from circuit.

I do not wish to be limited to the precise details of my inventionherein shown, as

changes may readily be made without departing from the spirit of theinvention; "but,

Having thus described my invention, l claim as new, and desire to secureby Letters Patent, the following:

1. A three-wire system of distribution having two main conductors and aneutral conductor between the main conductors, whereby the system isdivided into two sides, and having a wattmeter in circuit therewithwhose pressure-winding is subdivided into two portions, each connectedwith the neutral conductor of the system, each side of the systemincluding one of said portions, substantially as described.

2. A three-wire system of distribution having two main conductors and aneutral conductor between the main conductors, whereby the system isdivided into two sides, and having a wattmeter in circuit therewithwhose pressure-winding is subdivided into two portions, each connectedwith the neutral conductor of the systeln, each side of the systemincluding one of said portions, each main of the system including afield-winding of the wattmetercoaeting with the field produced by thepressure-winding in effecting the operation of the meter, substantiallyas described.

3. Athree-wire system of distribution having a wattmeter in circuittherewith whose pressure-winding is subdivided into two portions, eachside of the system including one of said portions, each subdivision ofthe pressure-winding being subdivided into armaturecoils,commutator-segments connected with the armature-coils, andcommutator-brushes engaging the commutator-segments, to include thecorresponding pressurewinding portion in circuit, substantially asdescribed.

4. Athree-wire system of distribution having a wattmeter in circuittherewith whose pressure-winding is subdivided into two portions, eachside of the system including one of said portions, each main of thesystem including a field-winding of the wattmeter coacting with thefield produced by the pressure-winding in effecting the operation of themeter, each subdivision of the 1inessure-wimling being subdivided intoarmature-coils,commutator-segments connected with the armature-coils,and commutator-brushes engaging the commutator-segments, to include thecorresponding pressure-winding portion in circuit, substantially asdescribed.

5. A three-wire system of distribution having a wattmeter in circuittherewith whose pressure-winding is subdivided into two portions, eachside of the system including one of said portions, each subdivision ofthe pressure-winding being subdivided into armatureeoils,commutator-segments connected with the armature-coils, andcommutator-brushcs engaging the eomniutator-segments, to include thecorresponding pressure -winding portion in circuit, the portions of thepressure-winding being mounted adjacent to each other and interposedbetween the aforesaid field-windings, substantially as described.

6. A three-wire system of distribution having a wattmeter in circuittherewith whose pressure-winding is subdivided into two portions, eachside of the system including one of said portions, each main of thesystem including a field-winding of the wattmeter coacting with thelield produced by the pressure-windingin effecting the operation of themeter, each subdivision of the pressure-winding being subdivided'intoarmature-coils,com mutator-segments connected with the armature-coils,and commutator-brushes engaging the commutator-segments, to include thecorresponding pressure-winding portion in circuit, the portions of thepressure-winding being mounted adjacent toeach other and interposedbetween the aforesaid field-windings, substantially as described.

7. A three-wire system, having two main conductors and a neutralconductor between the main conductors, whereby the system is dividedinto two sides of distribution, a watt- -meter in circuit therewithwhose pressurewinding is subdivided into two portions, each connectedwith the neutral conductor of the system, each side of the systemincluding one of said portions, each main of the system including afield-winding of the wattmeter coacting with the fleld produced by thepressure-winding in effecting the operation of the meter, eachsubdivision of the pressure-winding being subdivided into armaturecoils, commutator-segments connected with the armature-coils, andcommutator-brushes engaging the commutator-segments, to include thecorresponding pressure-winding portion in circuit, substantially asdescribed.

9. A three-wire system having two main conductors and a neutralconductor between the main conductors, whereby the system is dividedinto two sides of distribution, a wattmeter in circuit therewith whosepressurewinding is subdivided into two portions, each connected with theneutral conductor of the system, each side of the system including oneof said portions, each subdivision of vthe pressure-winding beingsubdivided into armaturecoils, commutator-segments connected with thearmature-coils, and commutator-brushes engaging the commutator-segments,to include the corresponding pressurewinding portion in circuit, theportions of the pressure-winding being mounted adjacent to each otherand interposed between the aforesaid field-windings, substantially asdescribed.

10. A three wire system having two main conductors and a neutralconductor between the main conductors, whereby the system is dividedinto two sides of distribution a wattl meter in circuit therewith whosepressurewinding is subdivided into two portions, each terposed betweenthe aforesaid held-windings,

substantially as described. 4

In witness whereof I hereunto subscribe my name this 6th day of October,A. D. 1904.

THOMAS DUNCAN.

" Witnesses:

JOHN E. DAL'roN, JOHN R. PFRAMMER.

